Democrats hold slim lead in Pennsylvania, race will likely head to recount - Huffington Post

Democrat Conor Lamb holds a narrow lead of 0.3 percentage points, or 579 votes over Republican state Rep. Rick Saccone late Tuesday with 99 percent of precincts reporting, a result that will likely end in a recount. 

"There is no automatic recount on the congressional district level in Pennsylvania, according to state law. Candidates can, however, petition for a recount within five days after counties complete their vote computations", according to Huffington Post. 

Meanwhile, the Associated Press is not declaring a winner because the race is too close to call.